We need a world boss that spawns at a certain time, players can join together to defeat the boss to gain rewards starting from common items to super rare items. 

Drops from boss:

Weapons or armour ranging from common to super rare, super rare drops have better stats and cannot be bought only obtained by boss. Drop chance is very low for super rare, can be sold to other players and listed on the market.

All players who participate will have a chance of getting loot from boss. RNG lets go. 

To add its own touch to this and not copy another game entirely, make something that involves cartel jobs, a co op job/boss fight.

We need something that involves co op, especially with the cartel members.

I have a rough idea for how this sort of thing might work in CE. Making it a horde sort of mechanic where there are a given number of targets rather than a single big boss. Can't say when I'll get to this though